1. Field of the Invention
The present invention relates to a motor for a hybrid vehicle, and particularly relates to miniaturization and weight reduction of the motor.
2. Description of the Related Art
As a motor for hybrid vehicles, there is for example a motor 10 as shown in FIG. 7, which comprises a rotor 6 with magnets 5 mounted on a peripheral section of a drive plate 4 provided between a crank shaft 2 of an internal combustion engine 1 and a transmission 3, and a stator 7 provided facing this rotor 6 in the radial direction. As a result, it is possible to rotate the rotor 6 about the same axis as the crank shaft 2, and to assist the drive of the engine 1 as well as regenerating part of the kinetic energy of the vehicle. The base section of the rotor 6 is integrally formed with the drive plate 4 by press-forming, so that a reduction in the number of parts and weight is achieved, as shown, for example, in Japanese Unexamined Patent Application, First Publication No. Hei 11-332010.
However, as the commercial application of hybrid vehicles advances, further improvement in performance is being investigated, and one major problem is weight reduction and miniaturization of some parts such as the battery and motor, etc for exclusive use in hybrid vehicles. In particular, for the motor 10 arranged between the engine 1 and the transmission 3 as described above, in addition to the need to consider the heights of the coil ends, their size has a direct effect on the outside dimensions of the drive system and transmission system. Therefore, further miniaturization of the motor is desired in order to realize more easy installation of the motor on the vehicle.